package cn.pli.bike.model.http;

import java.io.IOException;

import okhttp3.MediaType;
import okhttp3.RequestBody;
import okio.Buffer;
import okio.BufferedSink;
import okio.ForwardingSink;
import okio.Okio;
import okio.Sink;

/**
 * 自定义文件上传RequestBody
 * Created by：hcs on 2016/10/20 10:32
 * e_mail：aaron1539@163.com
 */
public final class FileRequestBody<T> extends RequestBody {

    /**
     * 实际请求体
     */
    private RequestBody requestBody;

    /**
     * 上传回调接口
     */
    private RetrofitCallback<T> callback;

    public RetrofitCallback<T> getCallback() {
        return callback;
    }

    public void setCallback(RetrofitCallback<T> callback) {
        this.callback = callback;
    }

    /**
     * 包装完成的BufferedSink
     */
    private BufferedSink bufferedSink;

    public FileRequestBody(RequestBody requestBody, RetrofitCallback<T> callback) {
        super();
        this.requestBody = requestBody;
        this.callback = callback;
    }

    @Override
    public long contentLength() throws IOException {
        return requestBody.contentLength();
    }

    @Override
    public MediaType contentType() {
        return requestBody.contentType();
    }

    @Override
    public void writeTo(BufferedSink sink) throws IOException {
        if(bufferedSink == null){
            //包装
            bufferedSink = Okio.buffer(sink(sink));
        }
        //写入
        requestBody.writeTo(bufferedSink);
        //必须调用flush，否则最后一部分数据可能不会被写入
        bufferedSink.flush();
    }

    /**
     * 写入，回调进度接口
     * @param sink
     * @return
     */
    private Sink sink(BufferedSink sink) {
        return new ForwardingSink(sink) {
            //当前写入字节数
            long bytesWritten = 0L;
            //总字节长度，避免多次调用contentLength()方法
            long contentLength = 0L;

            @Override
            public void write(Buffer source, long byteCount) throws IOException {
                super.write(source, byteCount);
                if(contentLength == 0){
                    //获得contentLength的值，后续不再调用
                    contentLength = contentLength();
                }
                //增加当前写入的字节数
                bytesWritten += byteCount;
                callback.onLoading(contentLength,bytesWritten);
            }
        };
    }

}
